Notes_01_02
3D Joints
Revolute
Prismatic
Helical (Screw)
Cylindrical
Universal (Hooke)
Globe (Spherical)
Flat (Planar)
R
P
H(S)
C
U(H)
G(S)
F(P)
Restricts
5
5
5
4
4
3
3
3D mobility
M = 6(nL-1) - 5 nJ1 - 4 nJ2 - 3 nJ3
Allows
1
1
1
2
2
3
3
1 of 6
Notes_01_02
Skeletal Diagrams
2 of 6
Notes_01_02
3 of 6
McPherson Strut
6
nL __________
2 (R,P)
nJ1 __________
1 (C)
nJ2 __________
C
PISTON ROD
4 (4G)
nJ3 __________
G
CHASSIS
TIE
ROD
STRUT
G
G
G
RACK
A-ARM
P
R
4
M __________
Notes_01_02
4 of 6
Stewart-Gough Platform (hydraulic)
14
nL __________
0
nJ1 __________
18 (12U, 6C) nJ3 __________
0
nJ2 __________
6
M __________
TOP PLATE
U
U
U
U
U
U
PISTON
C
C
C
C
C
C
CYLINDER
U
U
U
U
GROUND
U
U
Notes_01_02
5 of 6
Stewart-Gough Platform (electric)
20
nL __________
12 (6R, 6H)
nJ1 __________
12 (U)
nJ2 __________
0
nJ3 __________
6
M __________
TOP PLATE
U
U
U
U
U
U
NUT
H
H
H
H
H
H
SCREW
R
R
R
R
R
R
MOTOR
U
U
U
U
GROUND
U
U
Notes_01_02
6 of 6
Planar and Spherical Four Bar
4
nL __________
4
nJ1 __________
0
nJ2 __________
0
nJ3 __________
-2 ???
M __________